Instaling shift kit cranks

Discussion in '2-Stroke Engines' started by atomichurley, Jan 23, 2011.

  1. atomichurley

    atomichurley Member

    Hey Guys, i was installing the sbp hd right side cranks and free wheel today. i tightened it as tight as i could with a 3/8 ratchet and when i spin the crank the sprocket/freewheel assembly is not true.
    Should i tighten it very tight with 1/2 breaker bar?
    Would you recommend lubing the bottom bracket before slipping the crank onto it ?


  2. ocscully

    ocscully Member

    Shimano recommends aprox. 30ft. lbs of torque for crank bolts, but tightening the cranks tighter isn't going to get rid of the wobble you are talking about at the chainrings. The wobble is due to the single speed freewheel, and the relatively inexpensive steel chainrings. Unless the wobble is really excessive it won't be a problem. You do not want to put grease on the tapers of the bottom bracket spindle this joint should be dry.

  3. give me vtec

    give me vtec Active Member

    yeah dont grease it and tightening wont help either... unless its excessive enough to cause your chain to jump, dont worry about it.
  4. professor

    professor Active Member

    Try a different position, it is possible that the crank shaft is not true or that you are getting a stack up of tolerances. Mark where you are and rotate 180.
  5. Skyliner70cc

    Skyliner70cc Active Member

    Based on my experiences using the 2nd generation SBP shifter kit, the slightest amount of wobble caused the chain to jump. I replaced all of my cranks with sealed bearing/cartridge units and VIOLA, problems solved.
  6. Ghost0

    Ghost0 Guest

    A little wobble is normal, as long as your bottom bracket spindle is tight, What you are seeing is the fact that the square taper design of the crank system will not allow the cranks to be installed perfectly square to the spindle which causes the wobble. All square taper cranks do this but since the others don't have a front freewheel you can never see it because you can never hold the chainrings stationary while spinning the cranks. I have never had chains come off due to the normal wobble inherent with square taper cranks. Chain jumping is always alignment or tension issues. I have had them out as much as a 1/4 inch and had no chain jumping issues. Professor makes a good point in that some tolerance stack ups can make one of the 4 possible crank position better or worse so you should try all 4 cranks positions on the spindle to see if you can reduce it.
  7. atomichurley

    atomichurley Member

    Ok guys thats for the help, i'll try all the 4 different positions and see how its goes. i'll keep you guys updated when i take my new rocksolid 70cc hp kit for its first ride :)